Sewing machine



Fe'b. 8, 1938. N. v. cHRlsTENsEN Err AL 2,107,368

lSEWING MACHINE Filed June 12, 1936 4 SheetS-Sheel 1 l n Q L n n 1[NVEAiToRs Norman V'L'izrLsi/lzsn By 7121115 we@ TToRNEYs @Qw Mam,

Feb- 8, 1938. N. v. cHRlsTl-:NSEN ET Al. 2,107,368

SEWING MACHINE Filed June 12,4 1936 4 Sheets-Sheet 2 FIG. 1

INVENTORS:

ORNE YS.

Feb- 8, 1938. N. v. cHRlsTENsEN ET AL 2,107,368

SEWING MACHINE Filed June 12, 1936 4 Sheets-Sheet 3 ORNEYS.

Feb. 8, 1938. N. cHRlsTENsl-:N ET Al.

SEWING MACHINE Filed June l2, 1956 Patented Feb. s, 193sl NETE- TATESHacklander, Tinley Park, lll.,

assignors to Union SpecialMachine Company, Chicago, Ill., a corporationof Illinois Application .llunel 12,

2 Claims.

This invention relates to sewing machines; and it has reference moreparticularly to what are known as feed oi the arm sewing machineswherein the work being sewed is advanced outward of a supporting armincident to presentation to the stitching instrumentalities.

In sewing machines of the type specifically referred to relatively heavyrock'er arms are ordinarily employed to convert the rotary motion of anactuating shaft into back and forth movement of the parts, such, forexample, as the needle-carrying bars, which require reciprocation. Theaction of these rocker arms is attended by excessive vibration andresults in rapid wear of saidA arms and in the'parts connected withthem.

Our invention is directed toward overcoming arm sewing machineconveniently embodying our l invention, with the top cover plate of themachine removed and with portions of its frame broken away and sectionedto expose important parts which would otherwise be concealed.

Fig. II shows the front elevation of. the machine, likewise withportions broken away and in section to expose certain parts at theinterior. Fig. III shows the elevation of the left hand end of themachine with its drive Wheel and its` work-supporting arm removed; and

Fig. IV is atransverse section taken as indicated by the arrows IV-IV inFigs. *I- and' II.

As herein illustrated, the machine comprises a bracket-like frame I witha flat base 2 to rest upon a suitable table or other support, and withan integrallyformed, forwardly-projecting longitudinal tubular portion 3at an elevation above said base. Extending laterally from the tubularportion 3 of the machine frame at the left hand end, is a neck 4 whichterminates in a vertical head 5, and pendant from the right hand end isa boss-like projection 6 whereto is secured a work supporting arm 1Vwhich extends outward at an angle with its free end underreaching thehead 5. By suitable feeding mechanism (not illus- 1936, Serial N0.84,862

vanced voutward of said arm past the .needles indicatedat 8 of whichthere are two in the present instance. All the working parts of themachine derive their movements either directly or indirectly from a mainshaft 9 which extends axially through the elevated tubular portion 3 ofthe frame I and which is journaled in suitably spaced inset bearingbushings I9, II, I2, and I3. At its left hand protruding end, the shaft9 is provided with a combined hand and belt wheel I5 so that the machinecan be operated'either manually or under power. `Mounted on the shaft 9near the right hand en d are three eccentrics I6, I1 and I8, which,through the downward strap rods I9, 20 and 2| 'respectively associatedwith them, actuate the feed mechanism already referred to, and asuitable complemental stitch-forming means (not illustrated) thatcooperates with the needles 8 in a well known manner within the outerend of the work supporting arm 1. 'I'he usual presser foot of themachine is indicated at 22, and as shown is secured to the lower end ofa presser bar 23 coni-ined to up and down movement in guide bushings 25and 26 at the top and bottom of the head 5. 'Ihe presser bar 23 is'yieldingly urged downward by a leaf spring 21 which is anchored by astud 28 (Fig. III) projecting upward from a boss 29 on the frame I andextending forwardly along the top of the neck 4 and into the headl 5through anopening 3l) in the back of said head. The free end of thespring 21 reaches into a longitudinal slot 3I of the bushing 25and-bearsdirectly upon the rounded top end of the presser bar 23 asshown in Figs. II and III. A means is shown in Fig. III at 32 wherebythe pressure of the spring 21 may bev regulated. -The presser foot 22may be locked ln elevated position, when required,-by means of a camlatch 33 which cooperates with a lateral projection 34 of a collar 35secured to lthe presser bar 23vwithin the head 5. As shown in Figs. Iand III, the projection 34 of the collar 35 is engaged between a pair ofguide plates 3B respectively at opposite sides of a vertical slot 31 inthe outer end wall of the head 5, to steady the presser bar 23 in its upand down movements and at the same time prevent rotation thereof. Inorder that the presser foot 22 may be lifted in opposition to the spring21 during the sewing, the machineis fitted with a pedal control meansincluding a rock shaft 38 which extends into the back of the head 5, and

`at its inner end has an arm 39 with a stud 49 down movements of thepresser bar 23, see Figs. I and II. A lever 43 at the outer end of therock shaft 38 'is pivotally connected to the upper end of a link 45extending downward through a clearance hole 46 in the base 2 of themachine frame |.to a control pedal, not illustrated. After commonpractice the machine is further provided with a number of tensioningdevices 41, 48, 49 and 50 for the needle and looper threads used in thesewing, each of said devices including a pair of friction `discs 5|(Fig. II) which are free on stems 52 anchored in the machine frame andwhich are subject to regulatable springs 53. A slide plate 55 (Fig. I)operated concurrently with the presser foot lifting mechanism, carrieswedge projections 56 for engaging between the discs 5|.

of the devices 41-59 to relieve the tension on the threads.

Coming now to those features which constitute the subject of ourinvention, there is secured to the main shaft 9 immediately to the leftof the bearing a spiral gear wheel 51 which,.

a chamber 68 set apart within the neck 4 by across partition 69 whichsupports the bushing Il of the main shaft 9, and a dividing partition 16between said neck and head. From Fig. IV it will be observed that thechamber 68 has a depression 1I constituting a sump for oil which issplashed about by rotation of the gear 51 andy thus carried to the gears58 and 59 as well 'as to the bearings Il, 62, 63, 64 and 65 for theshafts 9, 6|) and 6|. The gears 51, 58 and 59 are accessible uponremoval of the cover plates 12 and 13 4respectively closing the front ofthe gear housing 61 and the top of the chamber 68. As shown in Figs. Iand H, the left hand end of the shaft 68 extends through the bearing 62into the hollow of the-head 5, and has secured to it a dynamicallybalanced crank disc 15 whereof the small diameter pin 16 is coupled, bymeans of a relatively light vertical link 11, with a correspondinglysmall diameter lateral stud projection 18 of a collar 19 on a bar 86which carries the needles 8, said bar being confined, like the.

presser bar 23, to vertical axial reciprocation by guide bushings 8| and82 set respectively into the top and bottom of the head 5. The outer endof the stud 18 on the collar 19 is attened at opposite sides, as at 83,and engages between a pair of vertical guide plates 85 secured to theinner side of the wall 66 ofthe head 5 ,(see Figs. I and Il) to restrainthe needle bar 80 against rotation and to take the lateral thrusts ofthe link 11. The various parts within the hollow of the head 5 arereadily accessible upon swinging aside of a frontal protection coverplate 86 which is attached by a thumb screw 81.

According to our` invention, the gears 51 and 59 are made withcomparatively small teeth differing in number by a few odd teeth fromthose of. the intervening idlerv 58 so that the shock loads attendantupon the operation of the needle bar will be apportioned between theteeth of said gears and the wear correspondingly distributed.

As a consequence of the described construction,

it will be apparent that the functioning .of the v needle bar actuatingmechanism will be smooth,

since the weight of the link 11 is compensated for by the balancing dfthe crank disc 15 and its lateral thrusts nullifled through connement ofthe stud 18 on the needle bar 86 to movement between the guide plates85, and since the shaft of the crank is `coordinated with the driveshaft 9 through the rotary gear train 51-59, so that the sewing machinecan be safely operated at high speeds without excessive noise andwithout vibration such as would result in rapid wear. The provisionsmade for self lubrication of the needle bar actuating mechanism precludethe necessity for any attention upon the part of the operator except forrenewal or replenishment of the oil in the sump at very infrequentintervals.

Having thus described our invention, we claim: 1. In a feed-off-the-armsewing machine, a frame having an elevated horizontal portionterminating in a hollow head, and a work supporting arm underreachingsaid head; a longitudinal drive shaft extending along the elevatedlongitudinal frameportion; a needle bar confined to verticalreciprocation inthe head; a needle actuating shaft substantiallyparallel to the longitudinalshaft and journalled within the head; atrain of gears connecting the needle actuating shaft with the driveshaft; operating connections within the head through which the needlebar is reciprocated from the needle actuating shaft; and partitioningwithin the head setting apart an oil chamber for the gear train toprevent splash oil from reaching the needle bar. 2. In afeed-off-the-arm sewing'machine,l a frame having an elevated hollowhorizontal portion with a laterally-projecting hollow terminal head atone endthereof, and a work supporting arm underreaching said head; alongitudinal drive shaft journaled within the horizontal portion of themachine frame; a needle bar confined to vertical reciprocation in thehead; a substantially parallel needle-actuating shaft in the horizontalplane of the drive shaft and journalled within the head; a train ofgears connecting the y needle-actuating shaft with the drive'shaft;operating connections through which the needle bar is reciprocated fromthe needle-actuating shaft; and partitioning within the head settingapart an oil chamber for the gear train to prevent splash oil fromreaching the needle bar.

' NORMAN V. CHRISTENSEN.

HANS HACKLANDER. Y.

